Commit Graph

28 Commits

Author SHA1 Message Date
FRIGN 11e2d472bf Add *fshut() functions to properly flush file streams
This has been a known issue for a long time. Example:

printf "word" > /dev/full

wouldn't report there's not enough space on the device.
This is due to the fact that every libc has internal buffers
for stdout which store fragments of written data until they reach
a certain size or on some callback to flush them all at once to the
You can force the libc to flush them with fflush(). In case flushing
fails, you can check the return value of fflush() and report an error.

However, previously, sbase didn't have such checks and without fflush(),
the libc silently flushes the buffers on exit without checking the errors.
No offense, but there's no way for the libc to report errors in the exit-

GNU coreutils solve this by having onexit-callbacks to handle the flushing
and report issues, but they have obvious deficiencies.
After long discussions on IRC, we came to the conclusion that checking the
return value of every io-function would be a bit too much, and having a
general-purpose fclose-wrapper would be the best way to go.

It turned out that fclose() alone is not enough to detect errors. The right
way to do it is to fflush() + check ferror on the fp and then to a fclose().
This is what fshut does and that's how it's done before each return.
The return value is obviously affected, reporting an error in case a flush
or close failed, but also when reading failed for some reason, the error-
state is caught.

the !!( ... + ...) construction is used to call all functions inside the
brackets and not "terminating" on the first.
We want errors to be reported, but there's no reason to stop flushing buffers
when one other file buffer has issues.
Obviously, functionales come before the flush and ret-logic comes after to
prevent early exits as well without reporting warnings if there are any.

One more advantage of fshut() is that it is even able to report errors
on obscure NFS-setups which the other coreutils are unable to detect,
because they only check the return-value of fflush() and fclose(),
not ferror() as well.
2015-04-05 09:13:56 +01:00
FRIGN 9144d51594 Check getline()-return-values properly
It's not useful when 0 is returned anyway, so be sure that we have a
string with length > 0, this also solves some indexing-gotchas like
"len - 1" and so on.
Also, add checked getline()'s whenever it has been forgotten and
clean up the error-messages.
2015-03-27 14:49:48 +01:00
FRIGN c9de9dd3c2 Audit cut(1)
1) Add check to parselist() to warn about an empty list.
2) Remove all "cut: "-prefixes from error-messages and other style
3) != -1 --> >= 0 and check for ferror on fp after getline.
4) Update usage with argv0.
5) argv-centric loop refactor
6) Properly report exit-status.
7) Add empty line before return.
2015-03-11 17:29:18 +01:00
FRIGN 833c2aebb4 Remove mallocarray(...) and use reallocarray(NULL, ...)
After a short correspondence with Otto Moerbeek it turned out
mallocarray() is only in the OpenBSD-Kernel, because the kernel-
malloc doesn't have realloc.
Userspace applications should rather use reallocarray with an
explicit NULL-pointer.

Assuming reallocarray() will become available in c-stdlibs in the
next few years, we nip mallocarray() in the bud to allow an easy
transition to a system-provided version when the day comes.
2015-03-11 10:50:18 +01:00
FRIGN 3c33abc520 Implement mallocarray()
A function used only in the OpenBSD-Kernel as of now, but it surely
provides a helpful interface when you just don't want to make sure
the incoming pointer to erealloc() is really NULL so it behaves
like malloc, making it a bit more safer.

Talking about *allocarray(): It's definitely a major step in code-
hardening. Especially as a system administrator, you should be
able to trust your core tools without having to worry about segfaults
like this, which can easily lead to privilege escalation.

How do the GNU coreutils handle this?
$ strings -n 4611686018427387903
strings: invalid minimum string length -1
$ strings -n 4611686018427387904
strings: invalid minimum string length 0

They silently overflow...

In comparison, sbase:

$ strings -n 4611686018427387903
mallocarray: out of memory
$ strings -n 4611686018427387904
mallocarray: out of memory

The first out of memory is actually a true OOM returned by malloc,
whereas the second one is a detected overflow, which is not marked
in a special way.
Now tell me which diagnostic error-messages are easier to understand.
2015-03-10 22:19:19 +01:00
FRIGN 3b825735d8 Implement reallocarray()
Stateless and I stumbled upon this issue while discussing the
semantics of read, accepting a size_t but only being able to return
ssize_t, effectively lacking the ability to report successful
reads > SSIZE_MAX.
The discussion went along and we came to the topic of input-based
memory allocations. Basically, it was possible for the argument
to a memory-allocation-function to overflow, leading to a segfault
The OpenBSD-guys came up with the ingenious reallocarray-function,
and I implemented it as ereallocarray, which automatically returns
on error.
Read more about it here[0].

A simple testcase is this (courtesy to stateless):
$ sbase-strings -n (2^(32|64) / 4)

This will segfault before this patch and properly return an OOM-
situation afterwards (thanks to the overflow-check in reallocarray).

2015-03-10 21:23:36 +01:00
FRIGN 31572c8b0e Clean up #includes 2015-02-14 21:12:23 +01:00
FRIGN b8b9d983c8 Add unescape() to libutil
formerly known as resolveescapes(), it is of central use to numerous
This drops a lot of LOC.
2015-01-29 21:52:44 +01:00
FRIGN 48bf88851a Add missing space in error message in cut.c 2015-01-24 23:09:09 +01:00
FRIGN c369844ae2 Refactor cut.1 and cut.c
and reflect recent changes to the role of "delim".
2015-01-24 22:53:37 +01:00
FRIGN 27996f2b86 Fix segmentation fault in cut(1)
Be stricter while resolving escapes in the delimiter-string and
error out when it has length 0 or contains an invalid escape.

Thanks to Hiltjo Posthuma's sharp eagle eyes this bug was spotted.
2015-01-24 21:26:48 +01:00
FRIGN 2277b619be Add support for arbitrary length delimiters in cut(1)
Having multibyte delimiters is not enough. For full flexibility,
the possiblity of cutting input lines with arbitrary length delimiters
is the real deal.
Given this functionality, it only sounds reasonable to also add support
to resolve escapes.
Thanks to Truls Becken for making the suggestion and designing such a
flexible cut(1)-implementation!
2015-01-22 20:27:54 +01:00
FRIGN 3946d1fcc9 Use the EARGF()-macro in cut.c 2015-01-22 16:36:07 +01:00
FRIGN 733b33f1c7 Add UTF-8-delimiter-support to cut(1)
Now you can specify a multibyte-delimiter to cut, which should
definitely be possible for the end-user (Fuck POSIX).
Looking at GNU/coreutils' cut(1)[0], which basically ignores the difference
between characters and bytes, the -n-option and which is bloated as hell,
one has to wonder why they are still default. This is insane!
Things like this personally keep me motivated to make sbase better
every day.

     NSFW! You have been warned.
2015-01-22 12:32:50 +01:00
FRIGN 76ca226e81 Add mandoc-manpage for cut(1) and clean up code
and mark it as finished in README.
2015-01-18 11:30:31 +01:00
Truls Becken 2433bb78cb cut: clean up file loop 2014-12-18 15:17:48 +00:00
sin 0d7822f866 Don't free the line buffer for each file
There's no point free-ing memory when the kernel can do it for us.
Just reuse the already allocated memory to hold lines.

Thanks Truls Becken for pointing this out.
2014-12-16 19:49:39 +00:00
Evan Gates 84b08427a1 remove agetline 2014-11-18 21:05:28 +00:00
FRIGN e17b9cdd0a Convert codebase to use emalloc.c utility-functions
This also definitely increases readability and makes OOM-conditions
more consistent.
2014-11-16 10:22:39 +00:00
FRIGN ec8246bbc6 Un-boolify sbase
It actually makes the binaries smaller, the code easier to read
(gems like "val == true", "val == false" are gone) and actually
predictable in the sense of that we actually know what we're
working with (one bitwise operator was quite adventurous and
should now be fixed).

This is also more consistent with the other suckless projects
around which don't use boolean types.
2014-11-14 10:54:20 +00:00
FRIGN eee98ed3a4 Fix coding style
It was about damn time. Consistency is very important in such a
big codebase.
2014-11-13 18:08:43 +00:00
sin 0c5b7b9155 Stop using EXIT_{SUCCESS,FAILURE} 2014-10-02 23:46:59 +01:00
Hiltjo Posthuma 97ca7c8b6d cut: improvements
- use agetline().
- code style.
- free allocated list.
- don't close stdin if "-" is given.
2014-06-01 18:02:13 +01:00
Hiltjo Posthuma daad071b31 cut, uudecode: free buf after use
Signed-off-by: Hiltjo Posthuma <>
2014-06-01 18:01:31 +01:00
sin b8edf3b4ee Add weprintf() and replace fprintf(stderr, ...) calls
There is still some programs left to be updated for this.

Many of these programs would stop on the first file that they
could not open.
2013-11-13 11:41:43 +00:00
sin 486d22fc48 Simplify code in cut(1)
Thanks Roberto and Rob for your input on this.
2013-10-10 23:04:46 +01:00
sin 484d5b4340 Do not rely on `s' being incremented before taking the address of it
The order of evaluation for the arguments of a function is not
defined by the standard.
2013-10-09 16:42:45 +01:00
Truls Becken 576a5ce55e Add cut(1) 2013-10-08 20:41:32 +01:00